Southern South America to Cape Horn and a frequent visitor to the Falkland Islands.
Description: Almost a goose-like swan, adult having a waxy-red duck bill, pink legs and small black wing-tips. Completely white except for black terminal third of outer six primaries. Unmistakable, the only white swan in the Neo-tropics, smaller and shorter-necked than other swans, adult at rest appears totally white with a brilliant waxy-red bill which is feathered to the base and lacks any basal knob; legs and feet bright pink. Iris yellowish to reddish orange. Juvenile: duller than adult, whitish but has patches of greyish-brown on crown, back and wings and blue-grey bill and legs. Becomes whiter during first winter, but some patches remain until adult plumage fully attained by second autumn.
Length 90-115cm (34-45in).
Males usually large than females.
In Flight: Swan-like shape and small black wing-tips are obvious in flight and present a unique combination in South America.
Voice: Has a loud trumpet-like call ‘cos-cor-oo’ the first syllable being longer and higher in pitch. Female’s calls are higher in pitch than those of the male. The species’ name is derived from the call.
Habits: A sociable bird in groups of about 100. Isolated pairs, rarely small loose colonies, build their bulky nest by tall fringe vegetation or on small islands by shallow water. Unlike swans of genus Cygnus, does not carry young on back. Post-breeding moulting flocks gather on favoured waters, where numbers may perhaps reach a couple of hundred individuals. It performs little understood migrations, confused by varying breeding seasons, dispersing northwards after the moult. It feeds by dabbling or wading in the shallows, sometimes by grazing on waterside pasture, walking easily with its relatively long legs. Its longer legs no doubt help it take to the air with greater ease than other swans, as it does not patter during take-off. Generally shy and wary.
Habitat: Fresh water lakes and lagoons, with fringe vegetation.
Population: Throughout its range this is quite a local bird. Concern had been expressed by the Chilean government which estimated that fewer than 1,000 remained in Chile in the late 1970s, and that these were confined to the extreme south of the country. As Chile is considered to be the main headquarters for this unique species, clearly there is urgent need for overall censuring throughout the bird’s range.